Mobile communication devices have become increasingly common in current society for providing wireless communication services. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Increased processing capabilities in such devices means that mobile communication devices have evolved from being pure communication tools into sophisticated mobile multimedia centers that enable enhanced user experiences.
A mobile communication device includes a radio frequency (RF) front-end module(s) (FEM(s)) configured to transmit an outgoing RF signal(s) and receive an incoming RF signal(s). The RF FEM is coupled to an antenna port(s) in an antenna element(s) that is configured to radiate the outgoing RF signal(s) into a wireless communication medium and absorb the incoming RF signal(s) from the wireless communication medium. In a conventional third-generation (3G)/fourth-generation (4G) mobile communication device, the RF FEM(s) is typically separated from the antenna element(s) and coupled to the antenna module(s) via an interconnect medium(s) (e.g., a conductive flex). Notably, the antenna port(s) inherently presents load impedance (e.g., 50Ω) to the RF FEM. As such, the RF FEM often employs an impedance matching circuit(s) to ensure proper impedance matching, but at the expense of added insertion losses.
In contrast to the conventional 3G/4G mobile communication device, a fifth-generation new radio (5G-NR) mobile communication device can be configured to transmit a millimeter wave (mmWave) RF signal(s) in an mmWave band(s) located above 12 GHz frequency. Notably, the mmWave RF signal(s) can be susceptible to attenuation and interference resulting from various sources. For example, the mmWave RF signal(s) can be attenuated due to insertion loss associated with the interconnect medium. As such, an mmWave FEM(s) is typically provided in close proximity (e.g., ≤100 micrometers) from an mmWave antenna element(s) (e.g., an antenna array) that radiates an outgoing mmWave RF signal(s) and absorbs an incoming mmWave RF signal(s). In some cases, the mmWave FEM(s) may even be integrated with the mmWave antenna element(s) to form an integrated FEM. In this regard, it may be desirable to take advantage of the close coupling between the mmWave FEM(s) and the mmWave antenna element(s) to help mitigate insertion losses resulting from the impedance matching circuit(s).